Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;

public class Main implements Runnable {

    public final String TASKNAME = "";
    public final boolean CONSOLE = true;

    public static void main(String[] args) {
        new Thread(new Main()).start();
    }

    BufferedReader br;
    PrintWriter out;
    StringTokenizer in;

    public String nextToken() throws IOException {
        while (in == null || !in.hasMoreTokens()) {
            in = new StringTokenizer(br.readLine());
        }
        return in.nextToken();
    }

    public int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    public double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    public long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    private void solve() throws IOException {
        String text = br.readLine();
        int result = 0;

        text = text.substring(1, text.length() - 1).replaceAll(", ", "");
        while (text.length() > 0) {
            String letter = text.charAt(0) + "";
            text = text.replaceAll(letter, "");
            result++;
        }
        out.print(result);
    }

    private void printSnake(int m) {
        for (int i = 0; i < m; i++) {
            out.print("#");
        }
    }

    private void printFreeSpace(int m) {
        for (int i = 0; i < m; i++) {
            out.print(".");
        }
    }

    public void run() {
        try {
            if (CONSOLE) {
                br = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(System.out);
            } else {
                br = new BufferedReader(new FileReader(new File(TASKNAME + ".in")));
                out = new PrintWriter(new File(TASKNAME + ".out"));
            }

            solve();

            out.flush();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }

    }
}